Carabiners are used for various applications in many different activities. Carabiners are typically associated with outdoor recreational activities, such as rock climbing, mountaineering, mountain rescue work, and sailing. However, carabiners are also employed in applications such as rescue work in urban and industrial settings, safety restraints in urban and industrial settings, law enforcement work, and military applications among many other applications.
Conventionally, a carabiner has a ring, or C-shaped body, having a gate, which may be opened to insert a rope, sling, or a belay/rappel device (e.g., a figure eight device or another belay/rappel device). The gate is shut, typically, by a spring that urges the gate closed. The gate may be a wire gate, comprising a loop of wire that may be biased toward the closed position. Oftentimes, the gate may be further secured in a closed position by a locking mechanism known as a sleeve, which locks the gate to prevent opening thereof.
Typically, a carabiner may have an elongated shape, such as an oval or a D-shape. FIG. 1A shows a conventional carabiner 100 having a generally C-shaped body 102 and a gate 104 pivotally secured thereto at a rivet area 110 of the C-shaped body 102. The elongated region of the body 102 is known as the spine 118 of the carabiner 100. The gate 104 may be pivoted inward, toward the spine 118, to an open position as shown in FIG. 1A. The carabiner 100 is depicted as a “locking” carabiner, having a sleeve 112 that may be employed to lock the gate 104 when it is closed. The gate 104 engages with a nose region 114 of the C-shaped body 102 when in a closed position, shown in FIG. 1B. The gate 104 includes a receptacle for receiving the nose region 114. The nose region 114 may flare outward at the proximal end 116, to abut the gate 104 during loading of the carabiner. A carabiner having such a gate/nose interface may be referred to as a keylock carabiner.
Conventional carabiners without a sleeve are known as “non-locking carabiners,” or simply as “carabiners.” Non-locking carabiners may be preferred in certain situations because they may be opened and closed more quickly, and are generally less expensive and lighter than locking carabiners. Non-locking carabiners have disadvantages. For example, a non-locking carabiner is more susceptible to having the gate pushed open, and becoming unclipped. A rappel device that is clipped into a carabiner may lever against the gate, pushing the gate open and enabling the rappel device to slip free. In another application, a carabiner may be clipped to a bolt hanger, which is attached to a bolt in a rock face. The carabiner may become twisted, with the gate against the bolt hanger, pushing the gate open and enabling the carabiner to unclip itself from the bolt hanger. A carabiner clipped to another object or device, such as another carabiner, a jumar, or a pulley, might also rotate to a position from which the gate is levered open and the carabiner is inadvertently unclipped.
The gate of a non-locking carabiner may also be inadvertently opened when the carabiner is pushed against a rock face or other object. This is dangerous, not only because the carabiner may become unclipped and detached from the object to which it is attached or a rope passing through the carabiner may become unclipped and detached, but also because the strength of the carabiner is compromised with the gate in an open position.
In certain falls, particularly when a rope has been “back-clipped,” the rope may cross back over the gate of the carabiner as the falling climber plummets past, levering the gate open. The rope may become unclipped and detached from the carabiner, causing the climber to fall further. Ideally, as the climber scales the cliff, a rope reaches from a belayer on the ground, up through at least one carabiner, which is attached to the cliff face and tied at the end to the climber. The rope should thread through the opening 130 of the carabiner from the ground, under the spine 118 of the carabiner 100, through the opening, and over the gate 104 to the climber. If the rope threads from the ground, over the spine 118 of the carabiner, and under the gate 104 as it continues upward to the carabiner, the rope is back-clipped. The rope passing under the gate 104 may cross over the gate if the climber falls.
Even with the use of a locking carabiner, the sleeve 112 may be a point of failure. For example the ability of the sleeve 112 to resist failure under an inward force may be much less than the overall strength of the carabiner. Carabiners manufactured for climbing use have a strength rating for tensile loading along their major axis 106, and a lesser strength rating along the minor axis 108. Carabiners do not have a minimum strength rating for a compressive (inward) force along the minor axis 108. Conventional locking sleeves have been known to fail under a body weight load, enabling the gate to swing open. With an open gate, the carabiner may fail under a lesser load, or become unclipped and detached.
Another disadvantage of a conventional locking carabiner is that an additional twisting motion is generally required to release the sleeve 112, in order to open the gate. This may be undesirable or even impossible to effect in a number of situations, for example when a rock climber is dangling from a cliff face with only one free hand, and would like to clip his or her rope through the carabiner. The twisting release motion may also be undesirable because the rope or another object may rub against the sleeve and twist it, resulting in an accidentally unlocked carabiner.
Accordingly, there is a need for a carabiner having an improved gate structure.